1. Field of the Invention
The present invention relates to sealing apparatus and methods, and more particularly to sealing apparatus and methods for sealing moisture permeation resistant pouches contained within an outer pouch.
2. Discussion of the Related Art
Packages for surgical instruments and elements, such as, for example, surgical suture-needles or sutures in general, constructed of moisture imperious materials are well known in the art. The material of which these packages are constructed usually include metallic foil outer layer, such as, for example tin or aluminum, which may be in laminate form with an inner layer of a thermoplastic heat sealable material which forms the interior surface of the package. Either before or after loading of the surgical instruments or elements, the inner pouches are heat sealed on three sides. The heat seal formed about the peripheral edge of the package may be supplemented by the addition of an adhesive material, such as, for example, polyethylene-based adhesive to facilitate bonding between the layers. The pouches are then sterilized in this open condition, typically by ethylene-oxide gas sterilization. After sterilization the pouches are transferred to a sterile room where the fourth side of the pouch is sealed and packaged into an outer pouch. The final step involves the resterilization of the inner and outer pouches, again by ethylene-oxide gas sterilization.
This method of packaging has several drawbacks which complicate the sealing and/or packaging of sterile surgical instruments and elements and may compromise the sterility of the packaged products For example, where sterilization precedes packaging of the surgical instruments, packaging equipment as well as the ambient environment must be maintained in a climate controlled sterile condition. This necessitates the provision of elaborate sterile facilities for handling, packaging and sealing of the surgical instruments and elements as well as resterilization of the packaging. Further, maintenance of the equipment and movement of the products in and/or out of this sterile environment is inhibited lest the sterility be compromised.
To simplify this sterilization process, outer breather packages were developed for sterilizing and maintaining packaged surgical instruments and/or elements. These breather packages usually comprise a sheet of clear or opaque plastic adhered to a paper, cardboard, spun-bonded polyolefin or other fibrous material backing to provide a sterile display environment for the enclosed surgical instruments and/or elements. The breather pouches are typically provided with a port or panel which is pervious to sterilizing gas such as ethylene oxide while being impervious to bacteria and other contaminants. In particularly useful embodiments a fibrous material constructed of spun-bonded polyolefin known as Tyvek (a registered trademark of DuPont), is used as the backing material with an outer layer of clear or opaque mylar/polyethylene laminate being heat or adhesive sealed to the periphery of the Tyvek to form the breather pouch.
The inner moisture permeation resistant pouch is similar to that described above and typically comprises a 3 ply laminate construction with a mylar/polyester outer ply, an aluminum foil ply and a polyethylene ply with an adhesive coating thereon.
Using the outer breather pouch, sterilization of the inner pouch and its contents is greatly simplified. For example, the product to be packaged is placed in the inner pouch, which remains at least partially open, and the inner pouch is then sealed inside the breather pouch. Thereafter, the breather pouch with its open inner pouch is subjected to a sterilization process wherein the contents of the inner pouch are gas sterilized inside the breather pouch. After sterilization the inner pouch is sealed through the breather pouch resulting in a finished packaged sterilized product.
This packaging method avoids the need for elaborate and extensive sterile facilities and permits easy handling and movement of the products without compromising sterility. However, one drawback to this packaging method is that a high degree of precision is required in the sealing of the partially open inner pouch through the breather pouch. The inner pouch is confined within the breather pouch but is not necessarily found in the same position in all instances. Thus there is some degree of non-uniformity with respect to where the inner pouch is disposed in the breather pouch at any given time. To insure adequate closure without damage to the contents of the inner pouch special care must be taken to achieve correct alignment of the inner pouch prior to the sealing step. Manually orienting the breather pouches prior to sealing such that the inner pouch contained therein is correctly positioned prior to directing the pouches into a sealer apparatus is an unacceptable solution since this procedure is labor intensive and time consuming, and susceptible to error necessitating constant vigilance by the operator or supervisor.
It would be highly desirable to have apparatus which would automatically process the breather pouches containing open inner pouches prior to sealing the inner pouch such that the inner pouch is properly oriented for accurate sealing.
Accordingly, it is one object of the present invention to provide apparatus which permits consistent accurate sealing of the inner pouches without affecting the outer pouches.
It is a further object of the present invention to provide apparatus wherein the position of the inner pouches within the breather pouches is determined prior to directing the sealer apparatus to seal the inner pouches.
Another object of the present invention is to provide a method for sealing an inner pouch within a breather pouch such that consistent accurate seals of the inner pouch are obtained.
These and other highly desirable and unusual results are accomplished by the present invention in an apparatus and method for sealing an inner pouch containing surgical instrumentation and/or elements through an outer pouch.
Objects and advantages of the invention are set forth in part herein and in part will be obvious therefrom, or may be learned by practice with the invention, which is realized and attained by means of instrumentalities, methods and combinations pointed out in the appended claims. The invention comprises the novel parts, constructions, arrangements, combinations, methods, steps and improvements herein shown and described.